Surface relaxation and stress of fcc metals: Cu, Ag, Au, Ni, Pd, Pt, Al and Pb

The multilayer relaxation at(100), (110), (111), (210), (211), (310), (311) and (331) surfaces of the fee metals Cu, Ag, Au, Ni, Pd, Pt, Al and Pb are calculated using the modified embedded atom method. The 'anomalous' outwar d relaxation at Al (100), (111), Pt(111), and Cu (111) surfaces is describe d correctly. The relief of surface stress and tension on the relaxation is studied on (111), (100) and (110) surfaces. In general, the surface stress in the direction of the surface normal determines the relaxation direction except for the Al (110) surface. When the surface stress is negative, the s urface relaxation is inward; otherwise, the relaxation is outward. An inter esting result is that the surface tension does not always decrease after re laxation. The outward relaxation will induce the increase in surface tensio n while the inward relaxation induces the decrease in surface tension.